Taxon Report

Tonestus peirsonii (Keck) G. Nesom & R. Morgan

Peirson's tonestus

Print Report

Taxon Summary

Tonestus peirsonii, commonly known as Peirson's tonestus, is a perennial herb in the Asteraceae that is found only in California. It occurs within Alpine boulder and rock field, and Subalpine coniferous forest (rocky), growing at elevations from 2900 to 3700 meters. Tonestus peirsonii is ranked 4.3, Plants of Limited Distribution, A Watch List; Not very threatened in California.

Classification


Scientific Name:	Tonestus peirsonii (Keck) G. Nesom & R. Morgan
Common Name:	Peirson's tonestus
Family:	Asteraceae
Element Code:	PDASTE0070
USDA Plants Symbol:	TOPE
Synonyms/Other Names:	Haplopappus peirsonii (Keck) J.T. Howell

Ecology and Life History


Lifeform:	perennial herb
Blooming Period: Jul-Aug	Jul-Aug
Elevation:	2900-3700 (9515-12140)
General Habitats:	Alpine boulder and rock field, Subalpine coniferous forest
Microhabitat:	Granitic
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	4.3
Global Rank:	G3
State Rank:	S3
State List:	None
Fed List:	None
Other Status:
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	0
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	0
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	0

Location


California Endemic: True
California Counties and Islands: Name (Code)
Fresno (FRE), Inyo (INY)
Quads: Name (Quad Code)
Mount Tom (3711836), Mt. Darwin (3711826), North Palisade (3711815)

Threat List Data from the CNDDB


Threat List Total:	0
EOs with Threat Listed:	Total EOs	% of EOs
	0	0 %

Notes



See Madroño 5(5):169 (1940) for original description, and Phytologia 68(3):178 (1990) for revised nomenclature.
Threats:

Taxonomy:

Selected References

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 7 November 2025].